how to insert data from form in c#.net :urgent

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Data.SqlClient; 
using System.Text;
using System.Windows.Forms;

namespace empinformation
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        DataTable dt;
        int currenrec = 0;
        int totalrec = 0;
       static SqlConnection con = new SqlConnection("user id=sa; password=123;database=work");

       static SqlDataAdapter da = new SqlDataAdapter("select * from emp", con);
        DataSet ds = new DataSet();
       
        private void button1_Click(object sender, EventArgs e)
        {
            
            da.Fill(ds, "emp");
            dt = ds.Tables["emp"];
            currenrec = 0;
            totalrec = dt.Rows.Count;
            FillControls();
            btnext.Enabled = true;
            btprev.Enabled = true;
        }
        private void FillControls()
        {
            txtemp.Text = dt.Rows[currenrec]["empno"].ToString();
            txtename.Text = dt.Rows[currenrec]["ename"].ToString();
            txtjob.Text = dt.Rows[currenrec]["job"].ToString();
            txtsal.Text = dt.Rows[currenrec]["sal"].ToString();
            txthrd.Text = dt.Rows[currenrec]["hiredate"].ToString();
           txtcom.Text = dt.Rows[currenrec]["comm"].ToString();
           txtdept.Text = dt.Rows[currenrec]["deptno"].ToString();
        }

        private void btnext_Click(object sender, EventArgs e)
        {
            currenrec += 1;
            if (currenrec >= totalrec)
            {
                currenrec = 0;
            }
            FillControls();
        }

        private void btprev_Click(object sender, EventArgs e)
        {

            currenrec -= 1;
            if (currenrec <= totalrec)
            {
                currenrec = totalrec-1;
            }
            FillControls();
        }

        private void btnew_Click(object sender, EventArgs e)
        {

            SqlCommand cmd = new SqlCommand();
        }

        private void btsve_Click(object sender, EventArgs e)
        {
          
        }
        private void btdel_Click(object sender, EventArgs e)
        {
            
        }
    }
}